1. Field of the Invention
The subject invention relates to firearms and more specifically to firearms having an indirect gas impingement system.
2. Description of the Prior Art
Firearms typically include a receiver that houses several working components of the firearm, including firing components, with a barrel extending from the receiver. There are various classes of firearms that operate in different manners. One class of firearm utilizes a bolt carrier is disposed in the receiver that is moveable between a firing position, from which a live round of ammunition can be fired, and a retracted position, from which a spent casing is ejected. The movement of the bolt carrier and ejection of the casing can be accomplished with a direct gas impingement or indirect gas impingement system. Examples of gas impingement type firearms include the M16, the M4®, such as the M4® carbine, and the AR-15®, such as the AR-15® Platform.
Firearms having the direct gas impingement system typically include an ejection port defined by the receiver. Direct gas impingement systems route exhaust gases back through the firearm to move the bolt carrier toward the retracted position. In particular, after firing the firearm, the direct gas impingement system routes exhaust gases, including any associated debris, from the barrel, back through a return tube to the bolt carrier, and out the ejection port of the receiver.
Firearms having the indirect gas impingement system do not route the exhaust gases back to the bolt carrier in an effort to reduce fouling caused by the exhaust gases that may occur with direct gas impingement type firearms. Instead, the exhaust gases are used to move a device, such as a piston, that engages the bolt carrier to move the bolt carrier toward the rearward position. The device of the prior art utilize multiple components to cause movement of the bolt carrier. Increasing the components causes an unwanted increase in the weight of the firearm. Further, increasing the components also causes serviceability problems with the bolt carrier and the device.
Therefore there remains a need to develop a firearm that utilizes an indirect gas impingement system that is light weight and simplified to provide easy serviceability and/or retro-fitting of the components.